How do you measure the quality of photo film?

The quality of photo film is based on how much light reactive chemicals are contained in the emulsion and whether, for color film, "true colors" are produced as a result of simple printing. An easy way to measure film quality is to see how much you can enlarge an image before you start to see graining and color deterioration, but you need to have Excellent camera and enlarger lenses or the results will be affected.